Method of manufacturing sounding boards for musical instruments



Patented Feb. 3, 1925.

UNITED STATES JAMES FREDERICK VEACO, OF BERKELEY, CALIFORNIA.

METHOD OF MANUFACTURING SOUNDING BOARDS FO'R MUSICAL INSTRUMENTS.

Application filed October 22, 1921. Serial No. 509,555.

which the following is a specification, in such full and clear terms aswill enable" those skilled in the art to construct and use thesame.

This invention relates to a method of making sounding boards for musicalinstruments and its object is to lighten the load on such soundingboards.

A further object of the invention is to lighten the weight of thesounding board and to improve the tone.

A further object of the invention is to make the sounding board strongerand to give it a better and more permanent crown, while at the same timemaking it more responsive to the string vibrations, whereby a rounderand fuller tone is produced.

A further object of the invention is to pro duce an initial strain inthe sounding board which will render the tone better than the ordinarysounding board.

Other objects of the invention will appear as the description proceeds.

An embodiment of the invention is shown in the accompanying drawings inwhich the same reference numeral is applied to the same portionthroughout, but I am aware that there may be modifications thereof.

Fig. 1 is a side elevation of the apparatus used in the manufacture ofthe sounding board.

Fig. 2 is a side elevation of the apparatus used in the manufacture ofthe sounding board looking in right angles of Figure 1.

Fig. 3 is a side elevation, and

Fig. 4 a plan view of one of the clamps for holding one of the ribsduring the stretching operations.

lFig. 5 is a side elevation and Fig. 6 a plan view of one of the clampsused at the opposite end of the ribs.

Fig. 7 is a view of the spring used for measuring the tension applied tothe ribs during the stretching operations, and

Fig. 8 is a side elevation of the sounding board after it has beenreleased from the press, showing the crown formed by the stretching ofthe ribs.

In producing a sounding board for musiclamps 0 cal instruments by thismethod, the sounding board is laid fiat upon any suitable table. Theribs are then stretched nearly to their breaking point, whereupon theyare glued permanently to the sounding board. A suitable apparatus isapplied to them to hold them tightly against the sounding board untilthe glue has had time to set, after which the strain on the ribs isreleased, and the sounding board may be removed from the table uponwhich it was laid, whereupon the contraction of the ribs causes theboard to be bent concave on the side the ribs are applied to, and owingto the initial stretching given the ribs they will always retain thecrown on the sounding board, since the crowning is due not to thebending of the ribs themselves which may in time cause a permanent setin them, but to the stretching of the material which immediately placesthe sounding board itself in a state of compression as soon as thestretching of the ribs is released. The apparatus used consists of apair of sawhorses 1 andiZ upon which a plurality of are placed. Theseclamps consist of heavy plates with upturned ends having open slots asindicated at 4, such a number of the clamps is used as may be required,the number being dependent entirely upon the size and stiffness requiredin the sounding board.

These clamps are loosely laid upon the sawhorses so that they may bemoved to any desired position, and upon them is loosely placed a. heavyfiat board 5 which forms the table upon which'the sounding board 6 islaid.

Yokes Tin such number as may be desired are secured to the edge of theboard 5, and each yoke is provided with a screw 8, the ob ject being tohold three or more beams 9 down against the ribs 10 while the glue is inprocess of setting, ordinarily requiring 18 to 24 hours.

A clamp 11 having two prongs 12 and 13 to embrace one end of the rib isused at one end of each of the ribs. This clamp has a yoke 14surrounding its prongs 12 and 13, and a screw 15 is used to tighten theprongs against the rib to hold it rigidly. This clamp also has side lugs16 and 17 which engage the sides of the bars 3 adjacent the slots 4.

A somewhat similar clamp 18 is used at the other end of the ribs. It hastwo prongs 19 and 20 which embrace thewends of {the 1? ribs, whilea yoke21 with a set screwQQ at tords the means for tightening the prongs 19and 20 on the ribs: This clamp also has a threaded end 23 with a nut 24thereon for placing-a strain on the ribs;

A washer 25 is placed on the threaded rod end 23 and bears upon' a heavyspring 26;

the object beingto provide means whereby a given-load maybe appliedtoeachrib by measuring the "compression of each of the several springs:used;

When the sounding board hasbeen placed on the table 5," the :ribs areplaced thereon; the'clampsll and 18 are applied andihe desired pressureis app'liedtoeach ofthe ribs,

whereupon the glue is'applied to the under side'iof the ribs and thescrews 8 are operated to tighten the cross ,beams9 down againsttheiri-b's to hold them tightly in place until the gluehas been set.When the glue has set-between"tl1e ribs and sounding board thecla'mpsmaybe released and the ends of the. ribs may; then be cut off 'the desiredlength whereupon the sounding board will be bent as'illustratediii-Figure 8 with the. V ribs on :the concave. side.

In' practicerit has been found that it is possible to make ordinarypiano sounding boards crown sufficiently by using from SIX totenribs;ea'chotwhich is strained up to about. eight hundred poundsbefore being gluedittast to the board;

This refers to ribs about three-eighths of an 'inch'lthick andoneinchlwide. If heavier ribsyare' used the'cinitial'strain must beincreasedaccordingly; The actual amountof lengthening-10f the ribs underthe given strain is comparatively small [for when the.

elastic limit is reached the'rib is likely. to break with theapplication of very little additional stress; The wood'used maybe of anykind at present used in-sounding boards;

butfsomexspeciesof fir is most commonly usedfor'the' ribs. The soundingboards are usually made-up of several widthsof board of the desiredcharacter glued together to produce a board of the. desired width."

, stretching the ribs longitudinally, securing" the ribs rigidly tozthesounding board, and

thenrele'asingjthe strain upon the-ribs.

2." A method of producing soundingboards for musical instruments wh chcoinpi lSES' placing the sounding board upon a suitable surface; )lacingthe;1ibs'tl1e-reon,' stretching the ribs, rigidly 'securing the 'ribs to'thei' sounding board," and thereafter releasing the 'ribs from thestretchingapparatus and1i'cut--i ting them the'desired length:

3. A method of producing sounding boards" for 'muslcalx instrumentsWlll'Cll i comprises placingthe sounding board upon a suitable support,"placing the" ribs on the soundlngboard, stretching the ribs as maybedesired} gluing the .ribs to the. sounding board, se-

curing the ribs rigidly against movement until the glue has seemsthereafter releasing theribsand "cutting them the "desired length:

board ina stretched condition; and *then re Inoving'the strain from=theribswhereby the board is permanently crowned;

5. A method'ol reducing sounding boards for musical lnstrum'en-ts" whichconsists 1H1 stretching the ribs,'-secu'ringthemarigidly to the boardthroughout'the'ir length'while they V are "stretchd, andthen removing:the strain from the ribs whereby the-board iscrownedf Intestin'ionywhereof I have hereunto; set

my hand this ll'thr 'day of october 'A.--D;

JAMES FREDERICK vEAoo.

Witness FRANKLiN S Bu'oxrlr'n' method of producing sounding boards formusical lnStI11lI1eI1t'S"Wl1'1Cl1' consists-1n stretchingth'e'r1bs.-secur1ng them to the

